Measure your PD online with your phone camera

Yes. On an iPhone, the Pupillary Distance app uses the front camera and TrueDepth AR face tracking to measure the millimeter distance between your pupils — no ruler or printed card required. You get far PD, near PD, and left/right monocular PD, then type them into the checkout when ordering glasses online.

In a 2024 peer-reviewed comparison, a smartphone front-camera PD app differed from a clinical pupillometer by an average of 0.6 mm (95% limits of agreement −2.9 to +1.7 mm), which the authors found small enough to stay within spectacle-manufacturing tolerance. Because it uses real depth instead of a flat photo, it avoids the angle and parallax errors that make mirror-and-ruler measurements easy to get wrong — self-measurement in a mirror repeats to only about ±4 mm. For strong prescriptions, average two or three readings.

No. Tools that work from a 2D webcam usually ask you to hold a credit card or coin against your face so they have something of known size for scale. The iPhone's TrueDepth camera measures depth directly, so it doesn't need a reference object — you just hold the phone at arm's length and look at the camera.

A generic web PD form is just a text box — it doesn't measure anything; it assumes you already know your PD. A camera-based app actually measures it for you on the spot, gives you near and monocular values most forms skip, and keeps the result on your device.

No. The camera is used live only and the video is never saved. All measurements are stored locally on your iPhone — nothing is uploaded, there's no account, and the app is ad-free.